JPH11153091A - Slide member and refrigeration compressor using the slide member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hardly effect adhesion between an iron base substance and an aluminum base member and hardly effect exhaustion of an oil film on a slide surface and to provide excellent wear resistance. SOLUTION: This sintered compact used in various applications, such as a slide member or a slide bush, an Oldham's ring, and a vane used in various refrigeration compressors has at least a slide surface in which independent voids 51 on the surfaces of which openings 51a are formed. An oil film on a slide surface is held by the independent voids 51 to improve lubricity. For this purpose, in the independent voids 51, a ratio of a diameter equivalent to a circle of 10 μm or less (the degree of the voids with a size of 10 μm or less/ the degree of the voids of a whole) is 85% or more and the opening area factor of the independent void 51 of the slide surface is 5% of less, and density of a sliding body is 7.3 g/cm<3> or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration compressor used for refrigeration and air conditioning for various uses, whether for business use or non-business use.

[0002]

2. Description of the Related Art Electric compressors for refrigeration and air conditioning include reciprocating compressors, rotary compressors, and scroll compressors, all of which are used in home and commercial refrigeration and air conditioning fields. Have been. Currently, it is growing by making use of its features in terms of cost and performance.

[0003] Each type has a sliding portion in the compression mechanism itself and its driving mechanism, and wear and seizure of the sliding portion greatly affect the life of the refrigerating compressor.
Therefore, conventionally, for example, a slide bush provided between the rotating shaft and the crankshaft that transmits the rotational force of the electric motor to the rotating blade of the compression mechanism, which has a great effect on the life of the refrigerating compressor, and the rotating blade is fixed. An Oldham ring that supports the blades so that they rotate without rotating.
Alternatively, a sliding member such as a vane provided in the cylinder that slides on the inner surface of the cylinder, slides on the piston that is eccentrically rotated, and is driven by the piston, is formed of an iron-based sintered body to hold the lubricating oil. The hardness is increased by quenching to improve wear resistance.

As a result, in a conventional refrigeration compressor using a refrigerant containing chlorine, such as the specified Freon R12 or the designated Freon R22, the lubrication function by the extreme pressure effect of the chlorine contained in the refrigerant is helped. The slide bush, Oldham ring, vane, and the like have no particular problem in terms of life even in a maintenance-free refrigeration compressor.

[0005] Recently, however, it has been confirmed that specific freon and the like contain chlorine atoms in the molecule, which causes destruction of the ozone layer, and development and use of alternative refrigerants have been attempted.

As a highly practical alternative refrigerant, HFC (Hydro Fluoro Carbo) containing no chlorine is used.
n) "Hydraulic and pneumatic technology '9"
4.6. (Published by Nihon Kogyo Shuppan).

[0007]

However, when an alternative refrigerant is used, it does not contain chlorine, so that lubricating properties such as those of the conventional specific Freon cannot be expected. For this reason, the sliding conditions become severe, and the life is shortened if the conventional sliding mechanism is used. Specifically, slide bush, Oldham ring,
And the vane has a problem of wear and seizure. This is thought to be due to the fact that the lubricating property of the substitute refrigerant cannot be expected, and the oil film tends to be partially lubricated in a boundary lubrication state, leading to early wear and early seizure.

According to the experience of the present inventors, the slide bush, the Oldham ring, and the vane are disclosed in
Even if a sintered metal such as sintered iron added with Mo or Ni disclosed in Japanese Patent No. 2770 and having an oil-impregnating property due to vacancies is not very useful for improving the wear resistance under the use of an alternative refrigerant. . After conducting various experiments and examining this, the problem of wear resistance especially occurred on the sliding surface when pressure and load acted, and the reason was that the lubricant supplied to the sliding surface was affected by the pressure and load. It has been found that the oil penetrates deeply into the pores in the sintered metal and escapes therefrom, which may cause an oil film breakage on the sliding surface at an early stage.

In order to verify this, the present inventors conducted a so-called pore inspection on pores of a sintered metal material by a mercury intrusion method. The conventional sample subjected to the inspection is an iron-based sintered material having a composition of C: 0.1 to 1.0% by weight,
u: 0.5 to 3.0% by weight, Ni: 1.0 to 7.0% by weight, and Mo: 0.1 to 1.5% by weight were used after quenching. The test looks at the mercury intrusion per gram of sample, which corresponds to the total pore volume of the sample. The results are as shown in Table 1 below, and the total pore volume was 0.0118.
cc / g, and considerable intrusion of mercury was observed. Such a conventional sample

[0010]

[Table 1]

The density of the sintered bearing is about 7.0 g / cm ^3, which is higher than that of a sintered bearing which is usually about 6.8 g / cm ³ . Various investigations were made on the state of the pores of this conventional sample, and it was found that the sample had a structure as schematically shown in FIG. 3 (b). To describe this, wide pores a having openings a1 to the surface shown in black are scattered on the sample surface, and these wide pores a are about 40 μm to 50 μm in size, and the openings a1 are formed on the surface. It is connected to another hole a having the hole a or another wide hole a scattered in the sample without opening to the surface through a narrow connecting portion a2.

Here, the pores of the conventional sample can be said to be continuous pores. This coincides with the inspection result with a large amount of mercury infiltration, and a large amount of lubrication is caused on the sliding surfaces of the sliding members such as the slide bush, Oldham ring, and vane of the compressor under the environment where pressure and load are applied. This is consistent with the fact that the agent penetrates into the pores and the oil film tends to break.

JP-A-9-32770 also discloses that
The resin is impregnated into the pores of the sintered iron to prevent the lubricant from escaping into the pores under a high load and making it difficult to form an oil film. However, the property of retaining the lubricant by the pores is lost, and the cost is increased by the amount of impregnation with the resin.

On the other hand, Japanese Patent Application Laid-Open No. 5-33093 discloses that an iron-based sintered metal has 10 to 20% of residual vacancies therein, but has sufficient strength due to metal bonding and diffusion bonding between powders. In addition, it has an oil-impregnating effect of retaining lubricant in the residual pores and forms an oil film between the mutually sliding surfaces during sliding, so when used in a wet lubrication environment, it has excellent wear resistance and sliding Demonstrates its properties, but said that it is difficult to increase the weight, and as an alternative to this, the rapidly solidified aluminum alloy powder was hot forged at a temperature that does not impair the alloy phase in the metastable state of the material and formed and solidified Independent pores of 10 μm or less
A material having 5% remaining is disclosed as satisfying the required strength while securing wear resistance and sliding characteristics. In addition, Fe and Ni contained therein form an intermetallic compound with Al to increase the high-temperature strength, and Cu, Mg, and Mn improve mechanical properties such as strength and hardness. In addition, the residual pores cause an oil-impregnating effect in a wet environment and prevent seizure of parts. Further, it is described that since the remaining holes are fine independent holes, they easily withstand stress, and deterioration of grain boundaries due to penetration of an oxidizing atmosphere hardly occurs.

However, a crankshaft for transmitting the rotational force of the electric motor to the rotating blades of the compression mechanism, and an Oldham ring or a slide bush provided between the crankshaft and the rotating blades are slidably formed of the aluminum alloy powder. If a member is used, it cannot be used because the relationship with the swirl vane, which is made of aluminum, tends to be gold even if adhesion is likely to occur. In addition, there is a problem that the strength of the sliding member made of the aluminum alloy powder is inferior to that of the iron-based material when used for small parts such as Oldham rings.

JP-A-3-162559 discloses a sliding member made of an iron-based material having a porous oxide layer formed on the surface thereof. Further, a porous lubricant layer in which a solid lubricant is held is disclosed. However, since the pores are continuous pores using only the porous layer, the above problem cannot be solved. According to the experimental results of the present inventors, as shown by black circles in FIG.
It is as low as about 0 kgf.

Further, even if the pores are sealed with a solid lubricant, the pores cannot be completely sealed and the continuous pore state cannot be eliminated.
The above problem cannot be solved. In addition, the cost increases due to the sealing process. In addition, if the porous layer is worn during long-term operation or severe operation with maintenance-free equipment, reliability is lost. Further, when oxynitriding is performed on a thin part, the processing temperature is high, and the part is deformed and it is difficult to obtain the required accuracy, which is not suitable for an Oldham ring or the like.

Japanese Patent Application Laid-Open No. 54-13005 discloses that
In a metal sintered vane, a residual air hole in a base structure is sealed by dispersing a metal oxide and a metal oxide generated by a steam treatment, and a highly airtight sintered vane is disclosed. However, since the pores are not completely sealed even by the steam treatment, the escape of the lubricant due to the continuity of the continuous pores cannot be completely prevented.

An object of the present invention is to provide an iron-based material which is resistant to adhesion to other members such as an aluminum-based member and to be resistant to oil film breakage on a sliding surface based on such new knowledge. It is an object of the present invention to provide a sliding member having excellent wear properties and a long-life refrigeration compressor using the same.

[0020]

The sliding member of the present invention has independent holes, and the independent holes have a ratio of a circle-equivalent diameter of 10 μm or less (frequency of holes of 10 μm or less / total number of holes). Is 85% or more, and the opening area ratio of the holes on the sliding surface is 5% or less.

Thus, in the sliding member, the independent holes formed in the sliding surface allow the lubricant supplied to the sliding surface to enter through the opening in the sliding surface, and the holes are separated from each other. Because they do not communicate with each other, these independent holes retain the lubricant that has entered and continue to be supplied in a dotted state on the sliding surface, and retain the oil film, so that they exhibit good lubrication and improve seizure resistance And since it is sintered iron, even if there are holes, it has a higher strength than a sintered body of aluminum alloy powder due to metal bonding etc., and it has a crankshaft that transmits the rotation of the electric motor of the refrigeration compressor to the swirl vanes. It is suitable to be applied to a slide bush or an Oldham ring between the rotating blades. In addition, since these slide bushes and Oldham rings are iron-based, it is possible to prevent the occurrence of adhesion due to gold by making the hardness difference even if the sliding partner is the same iron-based material. If the sliding partner is an aluminum-based revolving vane, different metals are used, so that adhesion by gold can be naturally prevented, and the degree of freedom in selecting the partner material increases. In addition, the independent pores have a circle equivalent diameter of 10 μm or less (frequency of pores of 10 μm or less / frequency of whole pores).
Is 85% or more, and the opening area ratio of the holes on the sliding surface is 5%.
% Or less, good lubricating properties are ensured even when using a hydrocarbon-based HFC-based refrigerant or an HC-based hydrocarbon-based refrigerant, which does not contain chlorine, which has the most severe sliding environment. In addition, seizure resistance sufficient to satisfy maintenance-free is obtained. Specifically, seizure resistance higher than that of continuous holes in an HFC-based refrigerant atmosphere is obtained. For example, an ester oil is effective as a lubricating oil. When the ratio of the circle-equivalent diameter of 10 μm or less is 95% or more, seizure resistance more than that of the case of continuous pores in the conventional HCFC-based refrigerant atmosphere can be obtained.

The sliding member, which is an iron-based sintered body having independent pores, is obtained by repeatedly performing sintering after pressing a plurality of times. High-quality one that stably satisfies the above-mentioned void conditions. Preferably, the density is 7.3 g / cm ³ or more.

The refrigerating compressor according to the present invention includes a compression mechanism, an electric motor for driving the compression mechanism, a crankshaft for transmitting the rotational force of the electric motor to the rotating blades of the compression mechanism.
A sliding bush and / or an Oldham ring provided between the crankshaft and the rotating blade; the rotating blade is made of aluminum; and the slide bush is made of an iron-based ceramic having an independent hole at least on a sliding surface. It is characterized by a sliding member consisting of a united body, and the independent holes hold the lubricant supplied to the sliding surface by entering it and keep supplying it to the sliding surface in a dotted state. In addition to retaining the oil film and ensuring seizure resistance, even if there are holes due to the sintered iron, the slide bush or / and Oldham ring, which are small parts, are smaller than the sintered body of aluminum alloy powder. The required strength can be satisfied.

Furthermore, in this case, it is possible to prevent the adhesion of the rotating blades, for example, by making the hardness difference even if the rotating blades to be slid are the same iron system. Since different metals are used in the case of aluminum, adhesion due to gold can be naturally prevented, and the degree of freedom in selecting the material of the swirling blade is increased.

In addition, the slide bush has independent holes, and the ratio of the diameter of the independent holes is 10 μm or less (the frequency of the holes of 10 μm or less / the frequency of the total holes) is 85% or more. And the opening area ratio of the holes on the sliding surface is 5%.
By using the following sliding members, HFC-based refrigerants and HCs that do not contain chlorine, the sliding environment of which is the most severe,
Even when a combination of a hydrocarbon-based fluorocarbon refrigerant such as a refrigerant and an ester oil lubricating oil is used, good lubricity is ensured and sufficient seizure resistance is obtained to satisfy maintenance-free conditions. Will be Sufficient lubricity and seizure resistance were obtained even when a hydrocarbon-based hydrogen-based or hydrocarbon-free refrigerant was used, and the use of ester oil as a lubricating oil was suitable without any problem. .

Further, as described above, if the sliding member is repeatedly pressed and sintered a plurality of times, the sliding member becomes a high-quality one that stably satisfies the above-described hole conditions. Reliability is improved. The density of the sliding member is 7.
It is preferably at least 3 g / cm ³ .

The refrigerating compressor according to the present invention also has a piston which slidably contacts the inner surface of the cylinder and rotates eccentrically, and a vane provided in the cylinder so as to be in sliding contact with and follow the piston. The moving surface has independent pores, and the independent pores have a circle-equivalent diameter of 10 μm or less (frequency of pores of 10 μm or less / frequency of entire pores) of 85% or more,
When the vane is a sliding member made of an iron-based sintered body having an opening area ratio of pores of 5% or less on a sliding surface, the vane is also required to have a lubricating environment and pore conditions. It is possible to exhibit the same effect as the sliding member exerts, and for the same reason as the sliding member, the vane is obtained by repeatedly performing sintering after pressing a plurality of times, and Preferably, the density is 7.3 g / cm ³ or more.

Other objects and features of the present invention will be apparent from the following detailed description and drawings. Each feature of the present invention can be used alone or in combination in various combinations as much as possible.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below in detail with reference to FIGS.

(Embodiment 1) Embodiment 1 is an example of a horizontally mounted scroll compressor for refrigeration and air conditioning. As shown in FIG. 1, a compression mechanism 2 for sucking, compressing, and discharging a refrigerant is provided at one end inside a closed container 1. The stator 4 of the electric motor 3 for driving the compression mechanism 2 is located at the center of the closed container 1 and is fixed to the inner surface of the side peripheral wall of the closed container 1. Is connected to a crankshaft 6 which is a drive shaft of the compression mechanism 2, and is arranged such that a rotation axis thereof is substantially horizontal. The crankshaft 6 is provided with a main shaft 8 at one end of the compression mechanism 2 on the compression mechanism 2 side.
And the other end opposite to the main shaft 8 is welded and fixed to the inner surface of the side peripheral wall of the closed container 1 at the other end of the closed container 1. It is supported by the auxiliary bearing member 11 provided.

Bearings 9 and 12 are provided on a portion of the main bearing member 10 supporting the main shaft 8 and a portion of the sub bearing member 11 supporting the other end of the crankshaft 6. These bearings 9 and 12 support the rotation of the crankshaft 6, but also support the force generated on the crankshaft 6 when the compression mechanism 2 compresses the refrigerant by this rotational movement.

The lower part of the other end of the main bearing member 10 in the sealed container 1 is a lubricating oil reservoir 7, and the upper part is a discharge passage 121 for the refrigerant to the outside of the sealed container 1. Lubricating oil pump 1 driven by the other end of crankshaft 6
7 is provided. The lubricating oil pump 17 communicates with the lubricating oil reservoir 7 through a lubricating hole 6 a formed such that a suction port 17 a opens in the lubricating oil reservoir 7 and a discharge port 17 b extends vertically from the other end of the crankshaft 6 to the main shaft 8. Lubricate each sliding part of the mechanism 2 including the bearing part.

As shown in FIGS. 1 and 2, the compression mechanism 2 includes a fixed blade 20 having a spiral blade 21 rising on a mirror plate 22 and a spiral blade 31 having substantially the same shape as described above.
A plurality of compression chambers 41 are formed between the two by interlocking the swirling blade 30 rising up, so that the swirling blade 30 is caused to make a circular orbital motion with respect to the fixed blade 20 without rotating.

A rotation preventing rotation drive mechanism 42 for rotating the rotation blade 30 in a circular orbit without rotating is fitted into a slide recess 8a of the main shaft 8 so as to slide along a diameter line of the bearing bush 44a. Within
The swivel shaft 30a provided at the back eccentric position of the swirl blade 30 is rotatably fitted directly or via a bearing, and the swirl blade 30 is fixed between the main bearing member 10 and the swirl blade 30. An Oldham ring 43 is provided to support a rotating motion without rotating. As shown in FIG. 2, the Oldham ring 43 has protrusions 43 at two places on the diameter line of the surface facing the swirling blade 30.
a, projections 43b are provided at two positions on the diameter line of the surface facing the main bearing member 10, respectively, and both arrangements are oriented in directions perpendicular to each other. These projections 43a, 43b may be integral with the Oldham ring 43, but if they are separate, they can be replaced when damaged.

The Oldham ring 43 has a projection 43a.
Are fitted so as to be able to move in the direction in which the projections 43a are arranged by fitting into the radial grooves 30b provided at two places on the diameter line of the swirling blade 30, and the projections 43b are
The Oldham ring 43 is engaged with the two radial grooves 10 a on the diameter line of the fixing member 10 so that the projection 43 is formed.
It is supported so that it can move in the direction in which b is arranged. As a result, when the main shaft 8 rotates, the swirl vanes 30 move in cooperation with the Oldham ring 43 and the slide bush 44.
The fixed blade 20 is swiveled without rotating.

When the swirling blade 30 is swirled, the compression chamber 41 formed between the swirling blade 30 and the fixed blade 20 forms the end plate 2.
The refrigerant is sucked through the suction port 40 shown in FIG. 1 in the swirling from the open position on the outer peripheral side of the outer peripheral sides 2 and 32 to the closed position.
The refrigerant gradually compresses as the volume of the refrigerant gradually decreases. In a further turning process, the compressed refrigerant is discharged through the discharge port 45 while the compression chamber 41 starts to communicate with the discharge port 45 and the volume of the compression chamber 41 is further reduced. The discharged refrigerant is supplied to the refrigeration cycle connected to the outside of the closed vessel 1 through the discharge pipe 121 from the discharge passage 121 formed by the closed vessel 1, and then returned to the closed vessel 1 through the suction pipe 47. Thereafter, the same operation is performed. repeat.

However, the scroll compressor of the present invention is not limited to the hermetic type and the horizontal type, and may be used in various states and postures such as an open type or a vertical type. Alternatively, the present invention can be applied to all the stationary blades 20 and the revolving blades 30 which are meshed with each other to form a compression chamber 41 and are driven with a sliding member such as a slide bush 44 and an Oldham ring 43.

The sliding members of the slide bush 44 and the Oldham ring 43 are sealed, maintenance-free, and lubricated by the refrigerant when used in a refrigeration compressor using a chlorine-free refrigerant. The sliding conditions are strict because the durability cannot be expected, and the durability is a particular problem.

Then, based on the above findings, the present inventors have
While using the slide bush 44 and the Oldham ring 43 as conventional sliding members made of an iron-based sintered material,
In the prior art, various experiments were conducted with the aim of reducing the size of the holes, which were problematic in the past, and making them independent, and as a result, the slide bush 44 and the Oldham ring 43 were examined. A suitable sliding member was obtained. And since it is an iron system and no special treatment is required, the cost is low.

To explain this, C: 0.1 to 1.0% by weight, Cu: 0.5 to 3.
0% by weight, Ni: 1.0 to 7.0% by weight, Mo: 0.1
When a conventional sintering operation and a pressing operation are performed twice each on a quenched iron-based sintered body having a composition of about 1.5% by weight, a schematic diagram of FIG. As shown in (1), an iron-based sintered body having a pore structure in which independent pores 51 which are small and not continuous with each other were scattered was obtained. The independent holes 51 on the surface of the sintered body have openings 51a on the surface. This material was subjected to a pore inspection by the same mercury intrusion method as the conventional sample. The results are shown in Table 2 below, where the total pore volume was 0.0009 cc / g and the mercury

[0041]

[Table 2]

The amount of infiltration was significantly reduced as compared with the conventional case. The total pore volume in this case is only the independent pores 51 opened on the surface of the sample of the present example into which mercury enters.
The density of such a sample of this example is about 7.3 g / cm ³ . The size of the hole 51 is about 10 μm, which is smaller than that of the conventional sample. It should be noted that, even though the sintering operation and the pressing operation are performed twice, it is also effective to perform the operation more than three times depending on the conditions, for example, the setting of the temperature, the pressure of the pressing operation, and the like. Performing the operation several times is advantageous in that the operation is facilitated.

The present inventors formed a ring on each of the sample of the present embodiment and the above-mentioned conventional sample, and conducted a wear test under the same conditions using a high-pressure atmosphere wear tester as shown in FIG. Done. Both results were compared. Looking at the change in the friction coefficient with time, the friction coefficient of the conventional sample having a specific gravity of 7.0 g / cm ³ becomes extremely high because the load is about 100 kgf as shown by the line B in FIG. .
In the sample of this example of ³ g / cm ³ , as shown by the line A in FIG. 5, the coefficient of friction starts to increase slightly from about 250 kgf. In addition, in the wear test, as shown in FIG. 6A, in the conventional sample having a specific gravity of 7.0 g / cm ³ , the wear amount of the disk (the mating material) is 4 μm as shown in the rod B, whereas the specific gravity is 7 g / cm ^3. In the sample of this example of 0.3 g / cm ^{3, as in} the case of the rod A, it was as small as 1.2 μm. Furthermore, in the burn-in test,
As shown in FIG. 6B, the conventional sample having a specific gravity of 7.0 g / cm ³ has a weight of 93 kgf as in the case of the rod B, whereas the sample of the present example having a specific gravity of 7.3 g / cm ^{3 has} the value as in the case of the rod A. 289
kgf is remarkably high. Therefore, the sample of this example has high abrasion resistance and seizure resistance, is sealed and maintenance-free, and is liable to break the oil film using a hydrocarbon-based hydrocarbon or a hydrocarbon-based refrigerant containing no chlorine. Slide bush 44 and Oldham ring 4 of refrigeration compressor
By applying No. 3, sufficient durability corresponding to the design life was obtained.

When a refrigerant containing the least chlorine is used, if a lubricating oil compatible with the refrigerant is used, the sealed container 1
Since the lubricating oil compatible with the refrigerant passing through each of the internal parts accompanies the details of each mechanical sliding part in the closed container 1, the sliding member according to the first embodiment has a sliding part. It is particularly effective for improving the wear resistance of the steel. Examples of HFC-based refrigerants containing no chlorine include R134a and R12.
5, R32 and the like. In addition, examples of lubricating oils compatible with such refrigerants include ester oils. Other examples include ether oil and alkylbenzene oil. In the case of a hydrocarbon-based refrigerant which is an HC-based refrigerant, a lubricating oil which is hardly compatible, for example, a naphthenic mineral oil or carbonate is used to reduce the size of the refrigerant.

Further, in a seizure test on a comparative sample having a specific gravity of 7.1 g / cm ³ which is intermediate between the conventional sample and the sample of the present example, as shown by a bar C in FIG. It is 123 kgf, and there is some anxiety about the sliding member used under severe sliding conditions, and it is preferable to set the specific gravity of the sliding member made of an iron-based sintered body to 7.3 g / cm ³ or more. is there. However, the sliding member according to the first embodiment is used in other applications, used in an open-type maintenance refrigeration compressor, or used in various applications other than a refrigeration compressor. Depending on the application, the specific gravity does not necessarily need to be 7.3 g / cm ³ or more, and it is sufficient to satisfy that the holes 51 are independent holes 51 that are not continuous with other holes 51. It is. In addition, the effect of improving the wear resistance and seizure resistance by the holes 51 only involves the independent holes 51 opened on the surface of the sliding member, and the independent holes 51 are formed inside the sliding member. Does not have any effect on wear resistance. Therefore, it is sufficient that the independent hole 51 is provided on the sliding surface of the sliding member.

For example, when a sliding member having a predetermined shape is manufactured by forging using the above-described conventional sample,
The surface layer is compressed by mechanical pressure due to forging to increase the density and to make the continuous pores independent pores, so that a sliding surface of a predetermined density having independent pores on the surface can be formed. This also improves the wear resistance as described above. However, the method of forming such a surface layer is not particularly limited, and various methods may be considered and adopted. In addition, the composition of the sliding member is not limited to the above-described one, but may be any suitable for the intended use.

By the way, in the compressor 2 built in the sealed container 1 forming the refrigerant passage, in order to protect the environment, a severe lubricating environment such as using a hydrocarbon-based hydrocarbon or a hydrocarbon-based refrigerant containing no chlorine is considered. In order to cope with the problem by utilizing the oil film holding force of the independent holes as described above, the opening state of the independent holes 51 on the sliding surface has a great effect.

Therefore, the present inventors conducted further experiments and examined in detail the relationship with the holes 51 in such a lubricating environment. According to this, the result as shown in FIG. 7 was obtained. In FIG. 7, black circles indicate the oil film holding power in the case of continuous holes in an HFC-based refrigerant atmosphere without chlorine, Δ indicates the oil film holding power in the case of independent holes in an HFC-based refrigerant atmosphere without chlorine, and the broken line indicates chlorine. 5 shows the oil film holding power of a chlorine-free HFC-based refrigerant required to secure seizure resistance in the case of continuous pores in a HCFC-based refrigerant atmosphere having a certain temperature. In addition, there is a correlation between the oil film holding power and the seizure resistance, and it has been confirmed that as the oil film holding power is improved, the seizure resistance is also improved. Therefore, as can be seen from FIG. 7, the independent holes 51 have an opening area ratio of 5 on the sliding surface.
% Or less, the density of the sliding member is 7.3 g / cm ³ or more, and particularly, the ratio of the equivalent circle diameter of 10 μm or less (the frequency of pores of 10 μm or less / the frequency of all pores) is 85% or more. And sufficient seizure resistance to ensure good lubrication and satisfy maintenance-free conditions. Specifically, seizure resistance is obtained more than in the case of continuous pores in an HFC-based refrigerant atmosphere without chlorine. When the ratio of the circle-equivalent diameter of 10 μm or less is 90% or more, seizure resistance higher than the case of continuous pores in the HCFC-based refrigerant atmosphere containing chlorine is obtained. The lubricating oil used was an ester oil compatible with the HFC-based refrigerant.

A sliding member made of sintered iron having such independent holes 51 can be easily obtained by repeating sintering twice after pressing as described above. By adopting and performing with the whole mold heated,
The above-mentioned vacancy conditions, density conditions and metal bonding are stable and of high quality.

(Embodiment 2) Embodiment 2 is an example in which the present invention is applied to a rotary refrigeration compressor as shown in FIG. The main structure of the refrigerating compressor according to the second embodiment is a general structure, and includes a cylinder 102 of a compression mechanism 100 installed together with an electric motor in a closed container 101.
The eccentric piston 103 inside is rotationally driven by the electric motor via the drive shaft, so that the tip 105a slides on the outer periphery 103a of the piston 103 and cooperates with the vane 105 that follows the outer periphery 103a, so that the cylinder 103 The compression chamber 104 formed between them is expanded and contracted,
When the pressure chamber expands, the refrigerant is sucked, and when the compression chamber 104 contracts, the sucked refrigerant is compressed and discharged, and is supplied to a refrigeration cycle.

However, the vane 105, which is a sliding member of such a refrigerating compressor, also has a problem in that a portion which is in sliding contact with the outer periphery of the piston 103 is easily worn. This is particularly problematic in severe sliding conditions that tend to cause oil film breakage using a chlorine-free hydrogen fluoride-based refrigerant. Therefore, the second embodiment
Then, the vane 105 has a specific gravity of 7.
The sliding member is made of an iron-based sintered body of ³ g / cm ³ or more. As a result, the vane 105 also has sufficient durability corresponding to the design life even under the severe sliding conditions of the refrigerating compressor.

A sliding member forming the vane 105;
Alternatively, depending on the sliding conditions, such as a sliding member used for other parts, those having various conditions shown in Embodiment 1 can be used.

[0053]

According to the sliding member of the present invention, since the lubricant containing the independent holes in the sliding surface is retained and supplied to the sliding surface in a dotted state, the oil film is maintained. Since it is a sintered iron, it has higher strength than a sintered body of aluminum alloy powder, and is suitable for application to a slide bush or Oldham ring of a refrigerating compressor. Also,
The sliding opponent of the slide bush and Oldham ring is an aluminum-based swirl vane. However, since they are mutually different metals and do not become gold, it is possible to prevent adhesion as in the case of both gold.

In addition, the refrigerant which does not contain chlorine in which the sliding environment is the most severe, in which the proportion of the independent pores satisfying 85% or more of the equivalent circle diameter of 10 μm or less and the opening area ratio on the sliding surface of 5% or less. In addition, when lubricating oil of ester oil is used in combination, good lubricity is ensured and seizure resistance sufficient to satisfy maintenance-free is obtained. Specifically, seizure resistance higher than that of continuous holes in an HFC-based refrigerant atmosphere containing chlorine can be obtained, and the equivalent circle diameter is 10 μm.
When the following ratio is 90% or more, seizure resistance higher than that of continuous pores in an HCFC-based refrigerant atmosphere containing chlorine can be obtained.

Since the sliding member is obtained by repeating sintering twice after pressing, a high-quality sliding member stably satisfies the above-mentioned hole condition. 7.3 density
It is preferably at least g / cm ³ .

According to each of the refrigerating compressors of the present invention, the slide bush, Oldham ring, and vane, which tend to cause a problem in durability for each type or for each part, are the various sliding members described above. The same operation as the sliding member in each case can be achieved to extend the life of the refrigerating compressor, and even if these are small parts having low strength, the sliding partner is an aluminum-based rotating blade. Even in environments where lubrication with refrigerants containing chlorine-free refrigerants is not possible, even in environments in which iron-based sliding parts become hotter, ester oil thermally decomposes and causes chemical wear. Even under the conditions, it is possible to satisfy a sufficient durability for maintenance-free operation by improving the lubricity and the seizure resistance. Also, by reducing the friction coefficient,
Since the sliding loss is reduced, the capacity of the compressor is improved.

That is, the input for obtaining the same capability can be suppressed, which can contribute to energy saving.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a scroll compressor according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a main part of the compressor of FIG.

FIGS. 3A and 3B are schematic diagrams showing the state of pores in a sintered body forming a sliding member, wherein FIG. 3A is an example sample of the first embodiment and FIG. 3B is a conventional sample.

FIG. 4 is a perspective view showing a state of a wear test for each sample of FIG. 3;

FIG. 5 is a graph showing a result of a change in a friction coefficient with time in a wear test.

FIG. 6 is a graph showing other results of the friction test, in which (a) shows the amount of wear in the friction test result, and (b) shows the seizure resistance.

FIG. 7 is a graph showing the relationship between the ratio of a circle-equivalent diameter of 10 μm or less and the oil film holding force of the iron-based sliding member having independent holes according to the present invention, and the conventional iron-based sliding member having continuous holes. It is a graph shown in comparison with the oil film retention force of a member.

FIG. 8 is a cross-sectional view of a rotary compressor according to Embodiment 2 of the present invention.

DESCRIPTION OF SYMBOLS 1, 101 Closed container 2, 100 Compression mechanism 3 Electric motor 6 Crankshaft 20 Fixed blade 30 Rotating blade 43 Oldham ring 44 Slide bush 103 Piston 105 Vane 107 Drive shaft

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F04B 39/00 F04C 18/356 A F04C 18/356 F25B 1/00 395Z F25B 1/00 395 C09K 5/04 // C09K 5 / 04 B22F 5/00 Z (72) Inventor Masahiro Tsubokawa 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (24)

[Claims] An independent hole having a diameter equivalent to a circle having a diameter of 10 μm or less (frequency of holes having a diameter of 10 μm or less /
A sliding member, wherein the sliding member is an iron-based sintered body having a total pore frequency of 85% or more and an opening area ratio of pores on a sliding surface of 5% or less. 2. Sintering after pressing is repeated a plurality of times to form independent cavities.
An iron-based sintered body having a ratio of 0 μm or less (frequency of pores of 10 μm or less / frequency of total pores) of 85% or more and an opening area ratio of pores on a sliding surface of 5% or less. A sliding member characterized by the above-mentioned. 3. The sliding member according to claim 1, which has a density of 7.3 g / cm ³ or more. 4. A compression mechanism, an electric motor for driving the compression mechanism, a crankshaft for transmitting the rotating force of the electric motor to the swirling blades of the compression mechanism, and a crankshaft between the crankshaft and the swirling blade. Having a slide bush provided,
The refrigerating compressor is characterized in that the slide bush is a sliding member made of an iron-based sintered body having an independent hole at least on a sliding surface. 5. The refrigerating compressor according to claim 4, wherein the swirl vanes are made of aluminum. 6. A compression mechanism, an electric motor for driving the compression mechanism, a crankshaft for transmitting the rotational force of the electric motor to the swirling vanes of the compression mechanism, and between the crankshaft and the swirling vanes. Having a slide bush provided,
The slide bush has independent holes, and the independent holes have a ratio of a circle-equivalent diameter of 10 μm or less (frequency of holes of 10 μm or less / frequency of entire holes) of 85% or more, and a sliding surface. A refrigeration compressor characterized by comprising a sliding member that is an iron-based sintered body having an opening area ratio of pores of 5% or less. 7. A compression mechanism, an electric motor for driving the compression mechanism, a crankshaft for transmitting the rotating force of the electric motor to the swirling vanes of the compression mechanism, and between the crankshaft and the swirling vanes. Having a slide bush provided,
This slide bush has sintering after pressing a plurality of times and has independent holes, and the independent holes are
Iron-based sintered body having a circle equivalent diameter of 10 μm or less (frequency of pores of 10 μm or less / frequency of total pores) of 85% or more and an opening area ratio of pores on a sliding surface of 5% or less. A refrigeration compressor comprising: 8. The refrigerating compressor according to claim 7, wherein the swirl vanes are made of aluminum. 9. The refrigerating compressor according to claim 6, wherein the density of the sliding member is 7.3 g / cm ³ or more. 10. The refrigerating compressor according to claim 6, wherein the refrigerant is a hydrocarbon-based hydrocarbon containing no chlorine or a hydrocarbon-based refrigerant. 11. The refrigerating compressor according to claim 10, wherein an ester oil is used as the lubricating oil. 12. A compression mechanism, an electric motor for driving the compression mechanism, a crankshaft for transmitting a rotational force of the electric motor to the compression mechanism, and a rotating blade that does not rotate with respect to a fixed blade. An Oldham ring for supporting a revolving motion, wherein the Oldham ring is a sliding member made of an iron-based sintered body having an independent hole at least on a sliding surface. Machine. 13. The refrigerating compressor according to claim 12, wherein the swirl vanes are made of aluminum. 14. A compression mechanism, an electric motor for driving the compression mechanism, a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism, and a rotating blade that does not rotate with respect to the fixed blade. An Oldham ring that supports a swinging motion. The Oldham ring has an independent hole in the sliding surface, and the independent hole has a ratio of a circle-equivalent diameter of 10 μm or less (a hole of 10 μm or less). Frequency / frequency of all holes)
Is 85% or more, and the opening area ratio of the holes on the sliding surface is 5%.
% Of a sliding member which is a ferrite sintered body of not more than 0.1%. 15. A compression mechanism, an electric motor for driving the compression mechanism, a crankshaft for transmitting a rotational force of the electric motor to the compression mechanism, and a rotating blade that does not rotate with respect to a fixed blade. And an Oldham ring that supports the oscillating motion.The Oldham ring is repeatedly subjected to sintering after pressing a plurality of times, and has an independent hole in a sliding surface. The ratio of the equivalent diameter of 10 μm or less (the frequency of pores of 10 μm or less / the frequency of all pores) is 8
A refrigerating compressor comprising a sliding member that is an iron-based sintered body having an opening area ratio of pores in a sliding surface of 5% or more and 5% or less. 16. The refrigerating compressor according to claim 15, wherein the swirl vanes are made of aluminum. 17. The refrigerating compressor according to claim 14, wherein the density of the sliding member is 7.3 g / cm ³ or more. 18. The refrigerating compressor according to claim 14, wherein the refrigerant is a chlorine-free hydrogen-hydrocarbon system. 19. The refrigerating compressor according to claim 18, wherein an ester oil is used as the lubricating oil. 20. A piston slidably in contact with the inner surface of the cylinder and rotating eccentrically, and a vane provided in the cylinder so as to slide and follow the piston, the vane has an independent hole in the sliding surface. The independent holes have a ratio of not more than 10 μm in the circle-equivalent diameter (the number of holes of 10 μm or less / the number of all holes) of 85% or more, and the opening area ratio of the holes on the sliding surface is 5%. % Of a sliding member which is a ferrite sintered body of not more than 0.1%. 21. A piston slidably in contact with the inner surface of the cylinder and rotating eccentrically, and a vane provided in the cylinder so as to slide in contact with the piston and to be driven by the piston. It has been repeated several times to have independent holes in the sliding surface.
An iron-based sintered body having a ratio of μm or less (frequency of pores of 10 μm or less / frequency of total pores) of 85% or more and an opening area ratio of pores on a sliding surface of 5% or less. A refrigerating compressor comprising a moving member. 22. The refrigerating compressor according to claim 20, wherein the density of the sliding member is 7.3 g / cm ³ or more. 23. The refrigeration compressor according to claim 20, wherein the refrigerant is a chlorine-free hydrocarbon-hydrocarbon system. 24. The refrigerating compressor according to claim 23, wherein ester oil is used as the lubricating oil.